There are, at present, floating vessels that incorporate an inflatable hull and that can be mainly equipped with a rudder, a centerboard well, a centerboard, a mast foundation base, a mast, and a sail. Patents U.S. Pat. No. 3,577,576, DE29919234, U.S. Pat. No. 4,149,481, U.S. Pat. No. 4,750,446, WO8606388 and DE3004416 are testimony to prior state of the art in the domain concerned.
The first disadvantage of these floating vessels that is known is due to the fact that the rigidity of their inflatable hull is lesser than that of a known floating vessel with a hull in a hard material. Consequently, their ability to support the weight of one or more crew members, and their ability to withstand the stresses applied by water and by the mast on the inflatable hull are limited or require the addition of bulky rigid structural reinforcements.
A second disadvantage of these known floating vessels is the shape of the bottom of their inflatable hull, which is flat. Consequently, their inflatable hull has lesser hydrodynamic performances and their behavior under navigation is of lesser quality than that of a known hull that has a bottom of non-flat transversal cross-section—for example, with a U-shaped or V-shaped general form, together with a non-flat longitudinal cross-section and a bow.
A third disadvantage of these known floating vessels is the complexity of assembly of the various pneumatic envelopes of which their inflatable hull is composed. Consequently, the time needed for their production, maintenance and any necessary repairs is long, and this has an unfavorable repercussion on the production costs. In addition, the complexity requires a consequential usage of materials, so these inflatable hulls have a relatively heavy weight. These disadvantages notably also apply to other forms of inflatable hulls covered in the patents JP2007176236, FR2722758 and US2011036284, which have a complex structure incorporating a peripheral buoyancy pudding fender, as well as a deck and transom. Also, the latter are mainly intended for motor propulsion, and do not have good nautical qualities when they are sail-powered because, in addition to being relatively heavy, they do not have a good water contact
A fourth disadvantage of these known floating vessels is the lack of structural rigidity of the assembly between the inflatable hull and the equipment of centerboarder type, which does not enable one to use a sail of comparable power to that on a centerboarder constructed in hard material. Consequently, their performance under navigation is lesser than that of known centerboarders constructed with a hull in hard material.
Also known through document US 2009/0031941 is a floating vessel of kayak type of which—in a known manner—the hull incorporates an inflatable bottom and sidewalls or pudding fenders that are also inflatable, and that are integral with each other. According to this document, each of the inflatable envelopes constituting the bottom and the lateral pudding fenders are made of a dual-wall material of which the walls are joined to each other by a multitude of joining threads. Inflation with air is done in the space between the two walls retained by the threads. Such a material offers the advantage of a good rigidity in the inflated state. However, the hull of the vessel according to document US 2009/0031941 has a relatively-complex conventional structure, which is prejudicial, notably from the viewpoint of production cost, weight, ease of use and reliability. Document US 2009/0031941 moreover states that, by choosing the length of the threads that extend between the walls, one can obtain inflatable compartments of any dimensions and form. Supposing that such a dual-wall envelope with joining threads of variable lengths is implementable, it would be a complex way of endowing a desired form on the inflatable compartments. Inflatable floating vessels of deck type with manual propulsion by paddle are also made of such dual-walled materials. The hull has no buoyancy chambers added to the envelope, has a relatively flat bottom, and has a front stem—in other words, a somewhat raised nose. Because of their flat bottom, these deck-type vessels have a nautical behavior that limits them to this board usage.